Please enable JavaScript.
Coggle requires JavaScript to display documents.
DEV 9: DEV OF SYNAESTHESIA (Synaesthesia Overview (when sense or percept…
DEV 9: DEV OF SYNAESTHESIA
Types
sequence-space synaesthesia
sound-vision synasthesia
lexical-gustatory synaesthesia
grapheme-colour synaesthete
report simple blue, rather than a particular concurrent (duck egg blue)
Evidence for Syn
Simner et al (2005)
example of similar colour choices fro synaesthetes and non-synaesthetes, but on syns have colour experience
Synaesthesia Overview
when sense or percept (inducer) causes a linked experience in another modality (concurrent)
is unidirectional
is automatic
consistent
idiosyncratic
concurrent experience is conscious
4% of population
Learning Synaesthesia
learn associations or statistical regularities
siblings in same environment have diff colours for inducers
synaesthetes with 10+ colour matches to magnets, graphemes which didn't match followed same pattern as non-magnet matching GC synaesthetes
Cross Activation
cross-wiring between areas responsible for processing certain info
explains GC synaesthesia, which was thought to be most common form - suggested genetic component & pruning of connections
Evidence For
Hubbard et al (2005)
synaesthetes when viewing black graphemes show activation in colour area V4 & grapheme area
inflated brain shows areas of activation
Theories of Developmental Synaesthesia
Changes Over Life
Stroop (1935)
synaesthetic stroop task
pairs inducer (grapheme) with congruent or incon matched concurrent (colour)
if shows interference - takes longer to complete task when inducer and concurrent don't match - shows there is automatic binding between con and inducer
stronger in ppl who to had more experiences of colours from the letters
Acquired Synaesthesia
Sensory Deprivation
Brain Damage
lesions on right thalamus in adulthood - sounds triggered perception of touch
acquired auditory-vis syn in adulthood from sensory deprivation or brain damage
Hypnosis
Drugs
Disinhibited Feedback and Re-Entrant
Disinhibited Feedback
feedforward activation travelling multiple pathway integration areas, feeds back down another pathway from insufficient disinhibition
Grossenbacher & Lovelace (2001)
Re-Entrant
similar to disinhibited feedback-adapted for GC - includes specific cortical areas involved
higher level processing feeds back to grapheme and colour processing areas
meaning of grapheme has to be identified before concurrent triggered
Smilek et al (2001)
Cascaded Cross-Tuning Model
updated cross-activation hypothesis
grapheme identification involves hierarchical feature analysis and between letter competition
cascaded cross-tuning model incorporates features of excitation, inhibition, X-activation, bottom-up, top-down processes